Close proximity or short-range wireless transmission protocols, such as Bluetooth (registered trademark) protocols, can be used to detect when two devices are in close proximity. However, some Bluetooth (registered trademark) technologies can consume more power than desired. Also, some users may be reluctant to have a Bluetooth (registered trademark) capability turned on at all times due to the risk of unsolicited messages (“BlueJacking”).
Some technologies may detect devices within a proximity of a beacon or transmission station. However, power is consumed when scanning for devices within proximity of the beacon.
Other low energy short-range wireless protocols have been designed to save energy. However, they still use a significant amount of energy scanning for other devices.